 /* RC522（RFID读写模块）的示例代码。
    Example code to RC522 ，RFID module.

    注意：确保设备在3.3伏而不是5伏的电压下使用。Duo GPIO（以及SPI）不能在5伏电平下使用。
    NOTE: Ensure the device is capable of being driven at 3.3v NOT 5v. The Duo
    GPIO (and therefore SPI) cannot be used at 5v.

    如果你想在5伏的电压下使用该模块，需要额外加装电平转换器转换SPI电平。
    You will need to use a level shifter on the SPI lines if you want to run the
    board at 5v.

    请按下面的注释接线，运行程序前请确保引脚复用在正确的功能上。
    Please wire according to the notes below and make sure 
    the pins are set for the correct function before running the program.

    SPI2_CLK -> SCK on RC522 Moudle
    SPI2_MISO -> MISO on RC522 Moudle
    SPI2_MOSI -> MOSI on RC522 Moudle
    19 -> NSS on RC522 Moudle
    20 -> RST on RC522 Moudle
    3.3v -> VCC on RC522 Moudle
    GND -> GND on RC522 Moudle

    UART3_TX -> RX on UART Moudle
    UART3_RX -> TX on UART Moudle
    GND -> GND on UART Moudle
 */

#include <SPI.h>

#define uchar unsigned char
#define uint unsigned int
 
//data array maxium length
#define MAX_LEN 16
 
/////////////////////////////////////////////////////////////////////
//set the pin
/////////////////////////////////////////////////////////////////////
const int chipSelectPin = 19;
const int NRSTPD = 20;
 
 
 
//MF522 command bits
#define PCD_IDLE 0x00 //NO action; cancel current commands
#define PCD_AUTHENT 0x0E //verify password key
#define PCD_RECEIVE 0x08 //receive data
#define PCD_TRANSMIT 0x04 //send data
#define PCD_TRANSCEIVE 0x0C //send and receive data
#define PCD_RESETPHASE 0x0F //reset
#define PCD_CALCCRC 0x03 //CRC check and caculation
 
//Mifare_One card command bits
#define PICC_REQIDL 0x26 //Search the cards that not into sleep mode in the antenna area 
#define PICC_REQALL 0x52 //Search all the cards in the antenna area
#define PICC_ANTICOLL 0x93 //prevent conflict
#define PICC_SElECTTAG 0x93 //select card
#define PICC_AUTHENT1A 0x60 //verify A password key
#define PICC_AUTHENT1B 0x61 //verify B password key
#define PICC_READ 0x30 //read 
#define PICC_WRITE 0xA0 //write
#define PICC_DECREMENT 0xC0 //deduct value
#define PICC_INCREMENT 0xC1 //charge up value
#define PICC_RESTORE 0xC2 //Restore data into buffer
#define PICC_TRANSFER 0xB0 //Save data into buffer
#define PICC_HALT 0x50 //sleep mode
 
 
//THe mistake code that return when communicate with MF522
#define MI_OK 0
#define MI_NOTAGERR 1
#define MI_ERR 2
 
 
//------------------MFRC522 register ---------------
//Page 0:Command and Status
#define Reserved00 0x00 
#define CommandReg 0x01 
#define CommIEnReg 0x02 
#define DivlEnReg 0x03 
#define CommIrqReg 0x04 
#define DivIrqReg 0x05
#define ErrorReg 0x06 
#define Status1Reg 0x07 
#define Status2Reg 0x08 
#define FIFODataReg 0x09
#define FIFOLevelReg 0x0A
#define WaterLevelReg 0x0B
#define ControlReg 0x0C
#define BitFramingReg 0x0D
#define CollReg 0x0E
#define Reserved01 0x0F
//Page 1:Command 
#define Reserved10 0x10
#define ModeReg 0x11
#define TxModeReg 0x12
#define RxModeReg 0x13
#define TxControlReg 0x14
#define TxAutoReg 0x15
#define TxSelReg 0x16
#define RxSelReg 0x17
#define RxThresholdReg 0x18
#define DemodReg 0x19
#define Reserved11 0x1A
#define Reserved12 0x1B
#define MifareReg 0x1C
#define Reserved13 0x1D
#define Reserved14 0x1E
#define SerialSpeedReg 0x1F
//Page 2:CFG 
#define Reserved20 0x20 
#define CRCResultRegM 0x21
#define CRCResultRegL 0x22
#define Reserved21 0x23
#define ModWidthReg 0x24
#define Reserved22 0x25
#define RFCfgReg 0x26
#define GsNReg 0x27
#define CWGsPReg 0x28
#define ModGsPReg 0x29
#define TModeReg 0x2A
#define TPrescalerReg 0x2B
#define TReloadRegH 0x2C
#define TReloadRegL 0x2D
#define TCounterValueRegH 0x2E
#define TCounterValueRegL 0x2F
//Page 3:TestRegister 
#define Reserved30 0x30
#define TestSel1Reg 0x31
#define TestSel2Reg 0x32
#define TestPinEnReg 0x33
#define TestPinValueReg 0x34
#define TestBusReg 0x35
#define AutoTestReg 0x36
#define VersionReg 0x37
#define AnalogTestReg 0x38
#define TestDAC1Reg 0x39 
#define TestDAC2Reg 0x3A 
#define TestADCReg 0x3B 
#define Reserved31 0x3C 
#define Reserved32 0x3D 
#define Reserved33 0x3E 
#define Reserved34 0x3F
//-----------------------------------------------

uchar serNum[5];
 
 
void setup() 
{ 
    Serial.begin(115200); 
     
    SPI.begin();
     
    pinMode(chipSelectPin,OUTPUT); // Set digital pin 10 as OUTPUT to connect it to the RFID /ENABLE pin 
    digitalWrite(chipSelectPin, LOW); // Activate the RFID reader
    pinMode(NRSTPD,OUTPUT); // Set digital pin 5 , Not Reset and Power-down
    MFRC522_Init(); 
}
 
 
void loop()
{
    uchar status;
    uchar str[MAX_LEN];
 
     
    // Search card, return card types
    status = MFRC522_Request(PICC_REQIDL, str); 
    if (status != MI_OK)
    {
        return;
    }
     
     
    // Show card type
    ShowCardType(str);
     
    //Prevent conflict, return the 4 bytes Serial number of the card
    status = MFRC522_Anticoll(str);
     
    if (status == MI_OK)
    {
        Serial.print("The card's number is: ");
        memcpy(serNum, str, 5);
        ShowCardID(serNum);
    }
 
    MFRC522_Halt(); //command the card into sleep mode 
 
    delay(200);
}
 
/*
 * Function：ShowCardID
 * Description：Show Card ID
 * Input parameter：ID string
 * Return：Null
 */
void ShowCardID(uchar *id)
{
    int IDlen=4;
    for(int i=0; i<IDlen; i++){
        Serial.print(0x0F & (id[i]>>4), HEX);
        Serial.print(0x0F & id[i],HEX);
    }
    Serial.println("");
}
 
/*
 * Function：ShowCardType
 * Description：Show Card type
 * Input parameter：Type string
 * Return：Null
 */
void ShowCardType(uchar* type)
{
    Serial.print("Card type: ");
    if(type[0]==0x04&&type[1]==0x00) 
        Serial.println("MFOne-S50");
    else if(type[0]==0x02&&type[1]==0x00)
        Serial.println("MFOne-S70");
    else if(type[0]==0x44&&type[1]==0x00)
        Serial.println("MF-UltraLight");
    else if(type[0]==0x08&&type[1]==0x00)
        Serial.println("MF-Pro");
    else if(type[0]==0x44&&type[1]==0x03)
        Serial.println("MF Desire");
    else
        Serial.println("Unknown");
}
 
/*
 * Function：Write_MFRC5200
 * Description：write a byte data into one register of MR RC522
 * Input parameter：addr--register address；val--the value that need to write in
 * Return：Null
 */
void Write_MFRC522(uchar addr, uchar val)
{
    digitalWrite(chipSelectPin, LOW);
 
    //address format：0XXXXXX0
    SPI.transfer((addr<<1)&0x7E); 
    SPI.transfer(val);
     
    digitalWrite(chipSelectPin, HIGH);
}
 
 
/*
 * Function：Read_MFRC522
 * Description：read a byte data into one register of MR RC522
 * Input parameter：addr--register address
 * Return：return the read value
 */
uchar Read_MFRC522(uchar addr)
{
    uchar val;
 
    digitalWrite(chipSelectPin, LOW);
 
    //address format：1XXXXXX0
    SPI.transfer(((addr<<1)&0x7E) | 0x80); 
    val =SPI.transfer(0x00);
     
    digitalWrite(chipSelectPin, HIGH);
     
    return val; 
}
 
/*
 * Function：SetBitMask
 * Description：set RC522 register bit
 * Input parameter：reg--register address;mask--value
 * Return：null
 */
void SetBitMask(uchar reg, uchar mask) 
{
    uchar tmp;
    tmp = Read_MFRC522(reg);
    Write_MFRC522(reg, tmp | mask); // set bit mask
}
 
 
/*
 * Function：ClearBitMask
 * Description：clear RC522 register bit
 * Input parameter：reg--register address;mask--value
 * Return：null
 */
void ClearBitMask(uchar reg, uchar mask) 
{
    uchar tmp;
    tmp = Read_MFRC522(reg);
    Write_MFRC522(reg, tmp & (~mask)); // clear bit mask
} 
 
 
/*
 * Function：AntennaOn
 * Description：Turn on antenna, every time turn on or shut down antenna need at least 1ms delay
 * Input parameter：null
 * Return：null
 */
void AntennaOn(void)
{
    uchar temp;
 
    temp = Read_MFRC522(TxControlReg);
    if (!(temp & 0x03))
    {
        SetBitMask(TxControlReg, 0x03);
    }
}
 
 
/*
 * Function：AntennaOff
 * Description：Turn off antenna, every time turn on or shut down antenna need at least 1ms delay
 * Input parameter：null
 * Return：null
 */
void AntennaOff(void)
{
    ClearBitMask(TxControlReg, 0x03);
}
 
 
/*
 * Function：ResetMFRC522
 * Description： reset RC522
 * Input parameter：null
 * Return：null
 */
void MFRC522_Reset(void)
{
    Write_MFRC522(CommandReg, PCD_RESETPHASE);
}
 
 
/*
 * Function：InitMFRC522
 * Description：initilize RC522
 * Input parameter：null
 * Return：null
 */
void MFRC522_Init(void)
{
    digitalWrite(NRSTPD,HIGH);
 
    MFRC522_Reset();
          
    //Timer: TPrescaler*TreloadVal/6.78MHz = 24ms
    Write_MFRC522(TModeReg, 0x8D); //Tauto=1; f(Timer) = 6.78MHz/TPreScaler
    Write_MFRC522(TPrescalerReg, 0x3E); //TModeReg[3..0] + TPrescalerReg
    Write_MFRC522(TReloadRegL, 30); 
    Write_MFRC522(TReloadRegH, 0);
     
    Write_MFRC522(TxAutoReg, 0x40); //100%ASK
    Write_MFRC522(ModeReg, 0x3D); //CRC initilizate value 0x6363 ???
 
    //ClearBitMask(Status2Reg, 0x08); //MFCrypto1On=0
    //Write_MFRC522(RxSelReg, 0x86); //RxWait = RxSelReg[5..0]
    //Write_MFRC522(RFCfgReg, 0x7F); //RxGain = 48dB
 
    AntennaOn(); //turn on antenna
}
 
 
/*
 * Function：MFRC522_Request
 * Description：Searching card, read card type
 * Input parameter：reqMode--search methods，
 * TagType--return card types
 * 0x4400 = Mifare_UltraLight
 * 0x0400 = Mifare_One(S50)
 * 0x0200 = Mifare_One(S70)
 * 0x0800 = Mifare_Pro(X)
 * 0x4403 = Mifare_DESFire
 * return：return MI_OK if successed
 */
uchar MFRC522_Request(uchar reqMode, uchar *TagType)
{
    uchar status; 
    uint backBits; //the data bits that received
 
    Write_MFRC522(BitFramingReg, 0x07); //TxLastBists = BitFramingReg[2..0] ???
     
    TagType[0] = reqMode;
    status = MFRC522_ToCard(PCD_TRANSCEIVE, TagType, 1, TagType, &backBits);
 
    if ((status != MI_OK) || (backBits != 0x10))
    { 
        status = MI_ERR;
    }
    
    return status;
}
 
 
/*
 * Function：MFRC522_ToCard
 * Description：communicate between RC522 and ISO14443
 * Input parameter：command--MF522 command bits
 * sendData--send data to card via rc522
 * sendLen--send data length 
 * backData--the return data from card
 * backLen--the length of return data
 * return：return MI_OK if successed
 */
uchar MFRC522_ToCard(uchar command, uchar *sendData, uchar sendLen, uchar *backData, uint *backLen)
{
    uchar status = MI_ERR;
    uchar irqEn = 0x00;
    uchar waitIRq = 0x00;
    uchar lastBits;
    uchar n;
    uint i;
 
    switch (command)
    {
        case PCD_AUTHENT: //verify card password
        {
            irqEn = 0x12;
            waitIRq = 0x10;
            break;
        }
        case PCD_TRANSCEIVE: //send data in the FIFO
        {
            irqEn = 0x77;
            waitIRq = 0x30;
            break;
        }
        default:
            break;
    }
    
    Write_MFRC522(CommIEnReg, irqEn|0x80); //Allow interruption
    ClearBitMask(CommIrqReg, 0x80); //Clear all the interrupt bits
    SetBitMask(FIFOLevelReg, 0x80); //FlushBuffer=1, FIFO initilizate
     
    Write_MFRC522(CommandReg, PCD_IDLE); //NO action;cancel current command ???
 
    //write data into FIFO
    for (i=0; i<sendLen; i++)
    { 
        Write_MFRC522(FIFODataReg, sendData[i]); 
    }
 
    //procceed it
    Write_MFRC522(CommandReg, command);
    if (command == PCD_TRANSCEIVE)
    { 
        SetBitMask(BitFramingReg, 0x80); //StartSend=1,transmission of data starts 
    } 
     
    //waite receive data is finished
    i = 2000; //i should adjust according the clock, the maxium the waiting time should be 25 ms???
    do
    {
        //CommIrqReg[7..0]
        //Set1 TxIRq RxIRq IdleIRq HiAlerIRq LoAlertIRq ErrIRq TimerIRq
        n = Read_MFRC522(CommIrqReg);
        i--;
    }
    while ((i!=0) && !(n&0x01) && !(n&waitIRq));
 
    ClearBitMask(BitFramingReg, 0x80); //StartSend=0
     
    if (i != 0)
    { 
        if(!(Read_MFRC522(ErrorReg) & 0x1B)) //BufferOvfl Collerr CRCErr ProtecolErr
        {
            status = MI_OK;
            if (n & irqEn & 0x01)
            { 
                status = MI_NOTAGERR; //?? 
            }
             
            if (command == PCD_TRANSCEIVE)
            {
                n = Read_MFRC522(FIFOLevelReg);
                lastBits = Read_MFRC522(ControlReg) & 0x07;
                if (lastBits)
                { 
                    *backLen = (n-1)*8 + lastBits; 
                }
                else
                { 
                    *backLen = n*8; 
                }
                 
                if (n == 0)
                { 
                    n = 1; 
                }
                if (n > MAX_LEN)
                { 
                    n = MAX_LEN; 
                }
                 
                //read the data from FIFO
                for (i=0; i<n; i++)
                { 
                    backData[i] = Read_MFRC522(FIFODataReg); 
                }
            }
        }
        else
        { 
            status = MI_ERR; 
        }
         
    }
     
    //SetBitMask(ControlReg,0x80); //timer stops
    //Write_MFRC522(CommandReg, PCD_IDLE); 
 
    return status;
}
 
 
/*
 * Function：MFRC522_Anticoll
 * Description：Prevent conflict, read the card serial number 
 * Input parameter：serNum--return the 4 bytes card serial number, the 5th byte is recheck byte
 * return：return MI_OK if successed
 */
uchar MFRC522_Anticoll(uchar *serNum)
{
    uchar status;
    uchar i;
    uchar serNumCheck=0;
    uint unLen;
     
    //ClearBitMask(Status2Reg, 0x08); //strSensclear
    //ClearBitMask(CollReg,0x80); //ValuesAfterColl
    Write_MFRC522(BitFramingReg, 0x00); //TxLastBists = BitFramingReg[2..0]
  
    serNum[0] = PICC_ANTICOLL;
    serNum[1] = 0x20;
    status = MFRC522_ToCard(PCD_TRANSCEIVE, serNum, 2, serNum, &unLen);
 
    if (status == MI_OK)
    {
        //Verify card serial number
        for (i=0; i<4; i++)
        { 
            serNumCheck ^= serNum[i];
        }
        if (serNumCheck != serNum[i])
        { 
            status = MI_ERR; 
        }
    }
 
    //SetBitMask(CollReg, 0x80); //ValuesAfterColl=1
 
    return status;
} 
 
 
/*
 * Function：CalulateCRC
 * Description：Use MF522 to caculate CRC
 * Input parameter：pIndata--the CRC data need to be read，len--data length，pOutData-- the caculated result of CRC
 * return：Null
 */
void CalulateCRC(uchar *pIndata, uchar len, uchar *pOutData)
{
    uchar i, n;
 
    ClearBitMask(DivIrqReg, 0x04); //CRCIrq = 0
    SetBitMask(FIFOLevelReg, 0x80); //Clear FIFO pointer
    //Write_MFRC522(CommandReg, PCD_IDLE);
 
    //Write data into FIFO 
    for (i=0; i<len; i++)
    { 
        Write_MFRC522(FIFODataReg, *(pIndata+i)); 
    }
    Write_MFRC522(CommandReg, PCD_CALCCRC);
 
    //waite CRC caculation to finish
    i = 0xFF;
    do
    {
        n = Read_MFRC522(DivIrqReg);
        i--;
    }
    while ((i!=0) && !(n&0x04)); //CRCIrq = 1
 
    //read CRC caculation result
    pOutData[0] = Read_MFRC522(CRCResultRegL);
    pOutData[1] = Read_MFRC522(CRCResultRegM);
}
 
 
 
/*
 * Function：MFRC522_Write
 * Description：write block data
 * Input parameters：blockAddr--block address;writeData--Write 16 bytes data into block
 * return：return MI_OK if successed
 */
uchar MFRC522_Write(uchar blockAddr, uchar *writeData)
{
    uchar status;
    uint recvBits;
    uchar i;
    uchar buff[18]; 
     
    buff[0] = PICC_WRITE;
    buff[1] = blockAddr;
    CalulateCRC(buff, 2, &buff[2]);
    status = MFRC522_ToCard(PCD_TRANSCEIVE, buff, 4, buff, &recvBits);
 
    if ((status != MI_OK) || (recvBits != 4) || ((buff[0] & 0x0F) != 0x0A))
    { 
        status = MI_ERR; 
    }
         
    if (status == MI_OK)
    {
        for (i=0; i<16; i++) //Write 16 bytes data into FIFO
        { 
            buff[i] = *(writeData+i); 
        }
        CalulateCRC(buff, 16, &buff[16]);
        status = MFRC522_ToCard(PCD_TRANSCEIVE, buff, 18, buff, &recvBits);
         
        if ((status != MI_OK) || (recvBits != 4) || ((buff[0] & 0x0F) != 0x0A))
        { 
            status = MI_ERR; 
        }
    }
     
    return status;
}
 
 
/*
 * Function：MFRC522_Halt
 * Description：Command the cards into sleep mode
 * Input parameters：null
 * return：null
 */
void MFRC522_Halt(void)
{
    uchar status;
    uint unLen;
    uchar buff[4]; 
 
    buff[0] = PICC_HALT;
    buff[1] = 0;
    CalulateCRC(buff, 2, &buff[2]);
  
    status = MFRC522_ToCard(PCD_TRANSCEIVE, buff, 4, buff,&unLen);
}
